NEET2006ChemistryElectrochemistryActual
E _ Fe 2+/ Fe ^ o =-0.441 ~V and E _ Fe ³⁺ Fe ²⁺ ^ O =0.771 V , the standard EMF of the reaction Fe +2 Fe ³⁺ 3 Fe ²⁺ will be:
Options
- A0.111 ~V
- B0.330 ~V
- C1.653 ~V
- D1.212 ~V
Correct answer
D. 1.212 ~V
Step-by-step solution
For the cell reaction aligned & Fe +2 Fe ³⁺ 3 Fe ²⁺ & Anode reaction is Fe Fe ²⁺+2 e ⁻ & Cathode reaction in 2 Fe ³⁺+2 e ⁻ & 2 Fe ²⁺ & E _ Cell ^ = E _ Cathode ^ - E _ Anode ^ & =0.771-(-0.441) & E _ Cell ^ =1.212 ~V & aligned Related Theory If the cell potential is negative, the reaction is reversed. In this case, the electrode of the galvanic cell should be written in a reversed order. Caution The positive potential indicates a spontaneous reaction